Documents to show cohabitation

[Kishorbm]

Hi,
I've got exactly 2 years from now to apply for my ILR along with my wife and 2 kids. I know its a bit early, but can someone help me by telling which documents are needed to prove that me and my wife are living together? I've checked the SET(O) form and its guideline but its not very clear reading them. Utility bills, bank documents? And those documents are needed only for last 2 yrs before application? I've read on other threads that you need 6 documents?
can someone please elaborate?
Thank you.
P.S - Dependents will be applying along with me using SET (O) form.

[geriatrix]

Refer to FLR(M) or SET(M) to understand the sort of documentary evidence(s) UKBA accepts as proof of cohabitation.